Tokyo is one of the world's largest and richest mega-cities and
also one of the most hazard prone (Alden, 1984; Cybriwsky, 1993; Fujita, 1991;
Geographical Review of Japan, 1990; Sassen, 1991). Since being founded
over 400 years ago it has been repeatedly devastated and rebuilt after fires,
earthquakes, and aerial bombings (Busch, 1962; Hewitt, 1983; Scawthorn et al.,
1985; Seidensticker, 1983, 1990). Usually the urgency of reconstruction
frustrated attempts to redevelop a formally planned city (Williams, 1993: 447).
Tokyo has also undergone a different kind of transformation with equally
profound consequences - first from provincial capital to pre-eminent national
urban centre and then to co-leading global city (Douglass, 1993; Harris, 1982).
Now, at the end of the twentieth century, as it awaits the possibility of
another major earthquake (Katsuhiko, 1987), Tokyo has had to cope with the
vicissitudes of high land costs, cramped living quarters, substandard housing,
lack of open space, severe traffic congestion, air pollution, and a rash of
terror gas attacks. In the face of these ills, as well as for other reasons,
there are strong pressures to relocate the national capital outside of Tokyo on
a safer site (http://www.keidanren.or.jp; http://www.infoweb.or.jp).

To confront its various threats the city has deployed an
arsenal of engineering technologies that far surpass in scale and sophistication
those of most other places. Indeed, Tokyo provides a striking example of the use
of high-technology means to manage high-stakes natural hazards; it also
highlights the role of centralized decision-making under conditions of
widespread public acceptance and cooperation. The potential appeal of this
approach to other disaster-vulnerable countries is one factor that underlies
Japan's leading role in the International Decade for Natural Disaster Reduction
(1990 - 2000). Although this case-study does not take up the issue of
limitations on Tokyo's methods of disaster mitigation, it will be important for
others to assess the circumstances in which this city's experience might be
applied elsewhere and to ask whether residents and leaders of Tokyo might in the
future become resistant to heavy public expenditures for massive
hazard-reduction projects.

The Tokyo Metropolis

Tokyo is one of Japan's three mega-cities (fig. 3.1). At its core
is the so- called 23 Wards Area, which encompasses the city as it existed in
1943, just before it was combined with the then-existing Tokyo Prefecture to
create an administrative region known as the Tokyo Metropolis.1 The
Metropolis now houses approximately 12 million people in a densely settled band
of 60 municipalities that wraps around the western side of Tokyo Bay and extends
into the adjacent Kanto Plain. Together with a lightly populated fringe of
plateaux, hills, and mountains to the west (the Tama District) and a number of
offshore oceanic islands, the built-up area is administered as one of Japan's 46
prefectures (fig. 3.2).

1

The Metropolis includes 23 wards, 26
cities, 7 towns, and 8 villages in a territory of 2,156 km2. Wards
were the basic unit of Tokyo's municipal government, but much of the urbanized
part of the metropolis now lies outside the "23 Wards Area'' of old Tokyo, (593
km2. This complicates the interpretation of urban data, which are
often presented separately for wards and other areas.

The Tokyo Metropolis is nested within two successively larger
administrative units. The Tokyo Metropolitan Region comprises the Tokyo
Metropolis and the prefectures of Chiba, Saitama, and Kanagawa. In addition to
Tokyo, this region contains Yokohama - a separate city of 3 million whose
history of disasters and human responses is almost as long and complex as
Tokyo's. In 1990 there were 31.8 million people in the Tokyo Metropolitan Region
- 25.7 per cent of the total population of Japan. The Metropolitan Region is, in
turn, part of the National Capital Region, which also comprises the prefectures
of Ibaraki, Tochigi, Gunma, and Yamanashi. The present chapter focuses on the
mainland districts of the Tokyo Metropolitan Region.

Urban evolution

Tokyo's predecessor city (Edo) was founded in 1603 but this
chapter begins with the formal birth of Tokyo as Imperial capital (1868).
Thereafter the city's growth can be divided into three phases: 1868 - 1923; 1923
- 1945; and 1945 - present. During the first period the city was in transition
from an old provincial city to a modern national capital. Population grew
steadily, from 1 million in the mid-1880s to 1.7 million in 1908 and 2 million
by 1920. Urban neighbourhoods spread outwards in all directions from the new
Imperial Palace near the city centre. This phase was brought to an end by the
Great Kanto earthquake and fire of 1923, which destroyed much of what was
already a very crowded city. The second period (1923 - 1945) was marked by
reconstruction of the destroyed neighbourhoods and rapid suburbanization,
particularly along major railroad lines that radiated north-west, west, and
south from the downtown core (fig. 3.3). During this time the formerly separate
built-up areas of Tokyo and Yokohama began to merge. By 1930 there were 5.5
million residents in the Metropolis and just over 7 million on the eve of the
Second World War. The third period (1945 - present) began after the devastation
of the Second World War, when Tokyo's population had fallen to around 3 million.
Post-war recovery reached a watershed in 1964 during the Tokyo Olympiad; from
then onwards the Japanese economy was so strong that the country became a
front-rank global economic power. By 1955 there were again more than 7 million
residents in Tokyo and by 1962 the total was over 10 million.

Fig. 3.1. The mega-cities of Japan

Fig.3.2. The Tokyo Metropolis (Source:
Tokyo Metropolitan Government)

Since the end of the Second World War, population has concentrated
in the Tokyo Metropolitan Region at rates that exceed those of Osaka, Nagoya,
and other metropolitan areas in Japan. Many of the nation's most important
political, economic, and cultural activities are located in Tokyo, especially
the central administration of the Japanese government, premier wholesale and
finance firms, the publishing industry, and leading educational institutions. In
addition, Tokyo now discharges rapidly growing international functions such as
banking, investment finance, and information dissemination; these reflect
Japan's recent rise to prominence in the global economy. While post-war
development has brought many benefits to the city, it has also contributed to an
extraordinary upsurge in land prices, severe traffic congestion, and
deterioration of the physical and social environments. Significant changes in
patterns of urbanization have taken place in every decade since 1945.

Much of Tokyo was demolished by air raids during the Second World
War. A total of 16,230 hectares (equivalent to about 40 per cent of the
urbanized area) was burned and 759,000 houses were destroyed. City
reconstruction projects received high priority from national and municipal
governments. Passage of the Special Urban Planning Act for War Disaster
Restoration (1946) ushered in a nationwide series of municipal land-use and
development plans. Tokyo's War Damage Rehabilitation Plan sought to keep the
city's population below 3.5 million. Additional population and industries were
to be accommodated in satellite cities and outer towns all over the Kanto Plain.
Post-war austerity and the weakly developed nature of municipal finance doomed
this plan almost from the outset. The Korean War, which broke out in June 1950,
marked a turning point in the economic fortunes of Tokyo. Private economic
investment and construction activities increased rapidly and land prices began
to soar. However, it proved difficult to implement large public urban
development projects.

The 1960s: Rapid growth

The 1960s were marked by rapid economic growth and equally rapid
urbanization of the Japanese population (Harris, 1982; Fujita and Hill, 1993).
More than a quarter of a million people flowed into the Tokyo Metropolitan
Region each year and buildings mushroomed everywhere. The Olympiad of 1964 was a
particular catalyst for change. Planners took advantage of the Olympic Games to
initiate projects that would help Tokyo achieve its new role as home to the
central management functions of a vast range of private and public institutions.
This included remodelling Tokyo's built-up area and building 117 km of new
expressways. The Tokaido-Shinkansen (Bullet Train) railway also came into
operation just before the Games opened. At the same time, the mega-city's
problems were becoming acute, as evidenced by the frequency of traffic-related
air pollution and a rash of disputes about sunlight deprivation owing to
construction of multi-storeyed buildings. Later in the decade, Tokyo's street
cars were largely abolished to improve traffic flow.

The 1970s: Budding disenchantment

Inner-city land prices were already high by the 1970s but now
suburban land prices also began to soar. Urban sprawl replaced compact
development as new housing sites were increasingly forced to locate further from
the city centre. For example, large-scale housing projects such as the Tama New
Town were started on the distant hilly lands south-east of Tokyo. Open space
declined drastically. Between 1945 and 1973 the proportion of open space fell
from around 47 per cent to less than 20 per cent (Nakazawa, 1988). Although some
mid-rise and high-rise housing was constructed on the sites of old factories
near the central business district, almost all new housing was expensive,
cramped, and far removed from workplaces. Significant clusters of new high-rise
buildings emerged in the inner suburbs, especially around important junctions
between radial and circumferential railroads.

Widespread signs of public disenchantment with the quality of life
in Tokyo marked the 1970s. In this respect the year 1973 was particularly
notable. For example, during March residents of Koto Ward forcibly blocked the
transportation of garbage from Suginami Ward through their neighbourhood after
people in Suginami Ward opposed construction of a new local waste incinerator.
This was a highly symbolic incident in an emerging "Garbage War'' brought on by
the onset of a mass consumption society, subsequent pollution, and delays in the
provision of waste-treatment facilities. In May, passengers damaged trains and
facilities at Ageo Station in Saitama Prefecture because of accumulated
discontent about overcrowded commuter trains and failures to extend the fast
rail service in step with the expansion of urban settlements. In June, the Tokyo
Assembly was confronted with residents' demands for the enactment of a Sunshine
Ordinance. These and other incidents were a sharp indictment of the costs
associated with fast economic growth, the concentration of central business
management functions, and failures of urban planning in Tokyo.

During the 1970s there were also significant changes in patterns
of urban migration. The inflow of new residents to the Tokyo Metropolitan Region
slowed and the locus of new population growth moved further out of the city. For
example, between 1970 and 1975, areas 30 - 40 km from the city centre
experienced the largest population increases. Between 1975 and 1980 the largest
population growth occurred in areas 40 - 50 km out. Conversely, resident
population declines in the Ward Area of Tokyo (i.e. the central city) began
during the 1960s and are continuing. This phenomenon is similar in appearance to
the decline of inner cities in many Western countries, although some of the
causes and consequences are different. For example, unlike North American
cities, population out-migration to the suburbs of Tokyo has not been
accompanied by increased rates of social pathology in the central city and land
prices there have remained at high levels.

Since 1980

Since 1980 Tokyo has undergone yet a further transformation.
According to one American observer:

Now that Japan has risen to become firmly established
as a global economic power, Tokyo is undergoing yet another rebuilding - the
third this century. This rebuilding is driven by money instead of by disaster,
and involves expansion of the city upward to new heights of skyscrapers, outward
to previously non-urbanized expanses of the Kanto Plain, to new land being made
in Tokyo Bay, and to a remarkable extent, downward to even greater depths of
subterranean construction. (Cybriwsky, 1993)

The Tokyo mega-city continues to dominate Japan, and many problems
of pollution, crowding, and declining quality of life that were noted during the
1970s have worsened. At the same time, deindustrialization of the metropolitan
area is occurring both because of international economic forces and because of
Japanese policies that encourage industries to relocate elsewhere. Between 1979
and 1986 there have been declines in the numbers of manufacturing plants, in the
industrial workforce, and in the total value of manufactured goods as the city
has shifted its focus to service industries.

Central-city land prices soared in the early 1980s as the yen's
value accelerated relative to the US dollar. High-rise offices, hotels, and
shopping centres became - and remain - the most typical buildings in the central
business district (CBD) and the 22 other regional commercial centres that are
scattered throughout the metropolitan region (e.g. Shinjuku). Important
settlement centres are springing up at considerable distances from the old city
core. They include residential communities 40 km west of central Tokyo in the
Tama district, the "science city'' of Tsukuba 65 km to the north-east, and new
industries clustered near the city's recently expanded international airport at
Narita (70 km east of the CBD). Meanwhile, high-status residential buildings are
beginning to be erected on former industrial sites near the city centre and more
attention is being paid to redressing the city's chronic lack of open space. For
the first time in the modern era, beaches are being created along Tokyo Bay to
improve recreational and aesthetic amenities for Tokyo residents.

Natural disasters in the Tokyo Metropolis

Hazard-susceptibility

Harris has pointed out that most Japanese cities are affected by
serious natural and industrial hazards but that, compared with third world
cities and North American cities, they are relatively free of urban social
hazards (e.g. shanty towns, slums, decaying inner cities, crime, social
conflicts) (Harris, 1982; Nakano, 1974). Tokyo closely fits that description.
Because of its low-lying coastal location near the junction of four highly
active tectonic plates, the Tokyo Metropolis is susceptible to a variety of
seismic hazards, including ground shaking, liquefaction, landslides, tsunamis,
and fires (Matsuda, 1980, 1990; Nakano and Matsuda, 1984; Terwindt, 1983). These
are compounded by subsidence problems connected with the withdrawal of
underground water and the compaction of filled land in offshore areas (Dolan and
Goodel, 1986; Matsuda, 1980). About 68 km2 of Tokyo now lie below sea
level, with an additional 57 km2 below high-tide level (Nakano et
al., 1988). The city also lies in the path of typhoons that sweep north and east
from the South China Sea and adjacent Pacific Ocean waters. In addition to
inflicting direct damage by means of flooding, winds, and heavy rainfall,
typhoons often trigger secondary hazards such as landslides and other ground
failures (Tamura, 1993). Widespread wind and water damage, including riverine
floods, occur occasionally; economic losses associated with heavy winter
snowfalls are more frequent. Although the imposing bulk of quiescent Mount Fuji
reminds many Tokyo residents of the potential for volcanic eruptions, the
likelihood of a damaging event from this source is generally considered to be
very low.

Concern about the susceptibility of Tokyo to another major
earthquake has been growing since the mid-1960s. For example, in June 1968 the
Tokyo Metropolitan Disaster Prevention Conference took up the issue of
evacuation routes that would be needed in the event of a future quake. Today,
much of the inner city is particularly at risk, including the main commercial
and governmental districts. Industrial plants, warehouses, and port facilities
that were built on filled land around the edges of Tokyo Bay and in deeper
waters further offshore are also at risk. So too are residential and artisanal
zones in the Koto Delta and elsewhere. Moreover, a large part of the
transportation infrastructure that ties together the entire metropolis occupies
areas that are susceptible to subsidence, inundation, or seismic disturbances.

Urbanization and hazard-susceptibility

The built-up area of Tokyo is sited on two kinds of land forms:
uplifted and dissected river and coastal terraces that comprise modestly hilly
inland districts (2 - 50 metres); and a series of floodplains (e.g. on the Edo,
Ara, Sumida, and Tama rivers) that cut across the terraces to form deltas along
the shores of Tokyo Bay (fig. 3.4). Dyking, filling, and reclamation projects
were begun as early as 1590 and have progressively moved the shoreline seawards,
especially during the twentieth century. These two subregions have been
characterized by contrasting patterns of human occupance throughout the history
of Tokyo, so much so that they are often referred to as the High City
(yamanote) and the Low City (shitamachi) (Seidensticker, 1983).
Tokyo's main middle-class and upper-class residential neighbourhoods are
generally located in the hillier districts, whereas the lowlands are primarily
occupied by commercial and industrial facilities as well as blue-collar housing.
For example, the Keihin Industrial Zone stretches for 40 km along the Tama River
and Tokyo Bay and is home to steel mills, machinery fabrication plants, and
chemical works. The portion of lowland that is sandwiched between the Ara and
Sumida rivers (i.e. the Koto Delta District) is now heavily occupied by housing
as well as other uses.

Fig. 3.4. Topography of Tokyo (Source:
Tokyo Metropolitan Government)

The lowlands have historically been more susceptible to natural
disasters than the upland terraces (Nakano et al., 1988). However, the relation
between urbanization and hazard losses is a complex one. For example, the need
quickly to provide housing for Tokyo's rapidly growing population after the
Second World War led to the construction of tightly packed masses of wooden
apartment buildings in western parts of the city. Many of these have been
replaced by reinforced concrete structures but dense clusters of inflammable
wooden buildings still remain in other places. There has also been an upsurge in
the use of city gas, propane gas, petrol, and kerosene throughout Tokyo. In
addition, the number of multi-storey buildings, the number of large-scale
underground shopping malls, and the volume of automobile traffic have all
increased. These changes have added to the disaster-vulnerability of the Tokyo
Metropolis. In summary, the general level of environmental hazard in Tokyo has
tended to increase because urbanization concentrates populations and
investments. Innovations of urban design and occupancy often introduce
unexpected patterns of exposure, and the potential for large losses has spurred
extra efforts to reduce both physical risks and human vulnerability.

Significant hazard events

Most natural hazard losses in 1963 - 1993 were caused by heavy
rain and high winds associated with typhoons and other storms, but non-damaging
earthquakes also occurred as well as an assortment of other hazards such as
winter blizzards. In an average year the city was affected by 5 - 20 significant
hazard events, but total annual numbers of affected households rarely exceed a
few thousand. In an unusual year (1966) typhoons disrupted or damaged almost
200,000 households; even more damaging storms have also affected Tokyo outside
this period of record (e.g. the Kanogawa typhoon, 1958). Severe earthquakes have
historically occurred at intervals of several decades, although none took place
between 1963 and 1993. Nevertheless, the threat of a major earthquake is treated
very seriously by Tokyo's leaders and its citizens.

Earthquakes and fires

Since 1615 the area that is today encompassed by Tokyo has
experienced at least six earthquakes of magnitude 5 or greater on the Japanese
scale (1615, 1649, 1703, 1855, 1894, 1923) (Matsuda, 1993).2 Two of
these quakes (1703 and 1923) were centred offshore in the Sagami Trough, which
bounds the Philippine Sea tectonic plate and the Pacific Ocean plate, and four
occurred directly under the site of Tokyo. Heavy losses were sustained in both
types of quake. For example, the 1855 event (M 7) caused the collapse of 14,000
dwellings with an estimated death toll of around 10,000 (Katsuhiko, 1987). The
Great Kanto quake of 1923 and the fire that followed killed 140,000 and
devastated approximately 44 per cent of the built-up area. The latter was the
most destructive natural disaster to have affected any of the world's large
cities during the twentieth century and one of the largest disasters to have
affected any community during recorded history.

2

On the Japanese Meteorological Agency
scale, 5 is roughly equivalent to VIII on the Modified Mercalli scale of
earthquake intensity.

Earthquake damage in Japan is closely related to weather
conditions that favour the spread of fires ignited by ruptured gas lines and the
scattered embers of cooking fires. For example, the Kanto earthquake of 1923
occurred just before noon at the end of a hot and dry summer when strong winds
were blowing. Non-earthquake-related fires have also been a frequent hazard.
Before the Second World War, the city was overwhelmingly composed of inflammable
wooden buildings. During the Edo period (1603 - 1868) there were at least 89
urban fires that burned large areas. It was said that new wooden buildings had
an average lifespan of seven years before being consumed by fire. Since the
1960s, the incidence of large fires has declined sharply as a consequence of
improved fire-fighting services and increased use of non-flammable materials in
urban buildings (Scawthorn, Arnold, and Scholl, 1985).

Floods

Tokyo is subject to three types of flooding: storm surges
associated with typhoons; heavy rainfall that fills low-lying areas directly;
and breaches in sea walls and dykes caused by earthquakes (Nakano et al., 1988).
Although there have been at least eight major surge floods since 1900 and
numerous rainfall floods, there has been no significant flood damage in the
Tokyo lowlands since 1966. This is primarily due to massive investments in
embankments, pumping stations, and water gates throughout the lowlands. In
contrast, flooding has increased in the upland tributary valleys. This
illustrates a well-known relationship between urbanization and increased
flooding as permeable undeveloped soils are replaced by impermeable roads,
parking lots, and buildings. The resulting pattern marks a dramatic shift in the
location of flood risks (fig. 3.5). For example, widespread flooding in
September 1949 inundated areas that were almost totally confined to the
lowlands. Nine years later the flood zone included valleys in the hillier
regions of the "tableland.'' By June of 1966 areas affected by urban flooding
were showing up on the west (inland) side of the Ward Area and flooding in the
lowlands was less of a problem.

Disaster mitigation

Public policies for disaster reduction in Tokyo are heavily
influenced by the city's experience with devastating fires. These have occurred
as a result of accidents, earthquakes (1923), and aerial bombings (Second World
War). Early efforts focused on fire awareness, fire prevention, and fire
fighting, and these are still central components of hazard management. For
example, residents and visitors are constantly reminded about the dangers of
fires by signs and information pamphlets; lay citizens are expected to provide
the first line of defence against fires; specialized local stores sell emergency
supplies; neighbourhood fire houses are stocked with ingenious lightweight
fire-fighting devices powered by human muscle and other portable energy sources;
and the Tokyo Fire Service is both highly trained and equipped with advanced
machinery for fire fighting and rescue operations. These kinds of responses are
already well developed and widespread throughout the city. A second tier of
protection is provided by various land-use and building construction measures
that are designed to: (1) retard the spread of fires; (2) provide shelters for
evacuees; and (3) supply relatively secure bases from which emergency
countermeasures can be mounted. In some parts of Tokyo all of these responses
are already in place, but elsewhere many are still being developed. Eventually
there will be a third tier of protection which is based on assumptions about the
prediction of risks and the reliability of "disaster-proofing'' technologies.
Residents may not only be forewarned about earthquakes and other threats by
sensors and monitoring devices; they will be provided with enough protection to
obviate the necessity of evacuation. Many of the adjustments to fires also serve
to offset other environmental hazards (e.g. earthquakes, industrial accidents)
but they do not necessarily guarantee protection against flooding, windstorms,
and landslides. Separate initiatives are sometimes undertaken for hazards such
as these.

Japan possesses a highly centralized, hierarchical form of
government, which is reflected in the disaster-mitigation process. This is
complemented by an extensive system of consultation and consensus-seeking among
different constituencies before policy changes are enacted. Although rancorous
conflicts are not precluded (and may become more frequent), there is rarely much
publicly voiced opposition to government edicts.3 National
legislation and policies set the context for local responses and it is
appropriate to begin with a brief review of disaster mitigation at the national
level.

Since the Meiji Restoration of 1868 a wide range of natural hazard
laws has been enacted in Japan (table 3.1). Between 1880 and 1911 there were
seven major national laws that addressed issues of flooding, erosion, and
disaster relief. After an interval of 36 years, marked by numerous earthquake
and typhoon disasters as well as the trauma of the Second World War, a renewed
round of national disaster legislation began in 1946.4 This continued
until 1980 and involved the passage of 35 additional acts and related
initiatives.

4

Curiously, the Great Kanto earthquake of
1923 did not spur many changes in national legislation, although it did
stimulate governmental investigations that gave a major boost to earthquake
research (Imamura, 1932).

The most important of these was the Disaster Countermeasures Basic
Act (1961). Other laws passed during this period addressed fire fighting, flood
control, forest conservation, slope failures, coastal hazards, heavy snowfall,
petrochemical complexes, and the prediction of earthquakes and volcanic
eruptions. In addition, several disaster science and management agencies were
established, an annual national "disaster prevention day'' (1 September - the
anniversary of the 1923 earthquake) was proclaimed, and legislation was enacted
to address the special problems of disasters in large cities. Particular
attention was directed towards the threat of future earthquakes in urban areas.

Since 1980 the pace of national disaster legislation in Japan
appears to have slowed. Only two major laws were passed in almost 15 years; one
of these was again directed at preparations for the anticipated Kanto earthquake
and the other focused on Japan's emerging role as a supplier of
disaster-management expertise to other countries. However, the Great Hanshin
earthquake that devastated Kobe in January 1995 may well stimulate an upsurge in
disaster-related legislation and other public policy initiatives. The pattern of
disaster legislation directly affecting Tokyo is somewhat different (fig. 3.6).
Disproportionately more laws and regulations were enacted during the period 1919
- 1924 (which encompasses the 1923 earthquake) and again in the years between
1952 and 1980. Whereas the pace of national legislation appears to have
decreased in recent decades, there has been no diminution of the legislation
affect- ing hazard management in and around Tokyo.

Establishment of Coordination Committee for Prediction of Volcanic
Eruption (Jun)

1975

Law on Prevention of Disaster in Petroleum Industrial Complexes
and Other Petroleum Facilities (Dec)

1976

Establishment of Hdqrs for Earthquake Prediction Promotion
(Oct)

1977

Establishment of "Tokai Area Assessment Council" (Apr)

Mt. Usu eruption (Aug)

1978

Large-scale Earthquake Countermeasures Act (Jun)

Izu-Ohshima-Kinakai earthquake (Jan)

Designation of "Areas under Intensified Measures against Tokai
Earthquake" (Aug)

Act on Special Measures for Active Volcanoes

Miyagi-ken oki earthquake (Jun)

1979

Establishment of "Prediction Committee for the Area under
Intensified Measures against Earthquake" (Aug)

1980

Special Fiscal Measures Act for Urgent Improvement Projects for
Earthquake Countermeasures in Areas under Intensified Measures against
Earthquake (May)

1982

Torrential rain in Kyushu (Jul)

1983

Nihon-kai-chubu earthquake (May)

Torrential rain in western Japan (May)

Miyakejima Is eruption (Oct)

1986

Izu-Ohshima Is eruption (Nov)

1987

Law concerning Dispatch of Japan Disaster Relief Team
(Sep)

1991

Mt Unzendake eruption (Jun)

Typhoon No. 19 hits whole of Japan (Sep)

1992

General Essentials of Countermeasures for Earthquake directly
beneath the South Kanto Area (Aug)

1993

Hokkaido-nansei-oki earthquake (Jul)

Cold-weather damage in northern Japan

Source Tokyo Metropolitan Government

The Disaster Countermeasures Basic Act (1961)

After the Second World War, Japan experienced a series of large
disasters, culminating in 1959 in the Ise Bay typhoon, which took a particularly
heavy toll (5,098 deaths) and prompted national leaders to adopt a wholesale
reform of the disaster-management system. Subsequently, the Disaster
Countermeasures Basic Act was promulgated in November 1961 with the goal of
developing a nationwide, comprehensive, governmental system for disaster
prevention.

This Act required the central government to form a Central
Disaster Prevention Council headed by the Prime Minister. Members of the council
are ministers and heads of designated administrative organs and designated
public corporations. The Council deliberates important matters relating to
disaster prevention and reports to the Prime Minister. The Council also prepared
the Basic Plan for Disaster Prevention in 1963. Individual administrative organs
are required to make their own Operational Plans for Disaster Prevention in
accordance with the Basic Plan. Local governments (prefectural governments and
municipalities such as cities, towns, and villages) are also required to
establish Prefectural Disaster Prevention Councils and Municipal Disaster
Prevention Councils. These bodies prepare Local (Prefectural and Municipal)
Plans for Disaster Prevention that define specific actions to be taken in their
respective areas.

Disaster countermeasures plan of the Tokyo Metropolitan
Government

The Prefectural Plan for Disaster Prevention

In accordance with the national Basic Plan for Disaster
Prevention, the Tokyo Metropolitan Government has prepared a Prefectural Plan
for Disaster Prevention. This plan is checked every year and amended when
necessary. It is printed in book form and available for sale to citizens. The
Earthquake Disaster Volume (last amended in 1986) alone consists of 803 pages of
information about appropriate disaster countermeasures.

There is a high level of concern about the potential effects of
large earthquakes on Japan. The earliest major legislative manifestation of this
is the Large-scale Earthquake Countermeasures Act (1978). Under the terms of the
Act, special measures have been taken to prepare for a massive earthquake that
may occur in or near Suruga Bay (the so-called Tokai earthquake). An intensive
earthquake observation system has been set up to monitor much of Kanagawa,
Yamanashi, and Shizuoka prefectures beyond the southern and western edges of the
Tokyo Metropolis. This system is designed to provide warnings of an impending
quake which will trigger various disaster prevention actions throughout the
region. According to most Japanese studies it is not expected that Tokyo
buildings would experience devastating effects from a repeat of the 1923 Kanto
(offshore) quake. Most of the worst physical impact would be felt further south
in Shizuoka Prefecture. However, there is concern about the possibility of
social disruption, panic, and loss of confidence in public authorities. A
Stanford University engineering researcher, Haresh Shah, has calculated that
economic losses might amount to US$ 1.2 trillion and other commentators have
speculated about the possibility that this scale of losses might trigger vast
global financial repercussions (Lewis, 1989).

In August 1992, the Expert Committee of the Central Disaster
Prevention Council pointed out that there was a significant possibility of a
Richter scale 7 earthquake occurring just beneath the South Kanto land area
(Saitama, Chiba, Tokyo, and Kanagawa prefectures) in the near future. At the
same time, the Council announced a set of guidelines for addressing the
consequences of such an event. These noted the difficulty of predicting this
kind of earthquake and the localized pattern of damage that would result. The
Metropolitan Government was charged to begin risk assessment of earthquakes in
the Tokyo Metropolis during fiscal year 1994, and the National Land Agency was
given responsibility for developing methods of assessing risks associated with
local quakes.

In Tokyo the system for coping with earthquakes is highly
detailed. The Metropolitan Government has enacted a Tokyo Metropolitan Ordinance
for Earthquake Disaster Prevention (1971). A specific Plan for Earthquake
Disaster Prevention has been developed and is updated every five years. It
includes a provision that requires the Metropolitan Government to assess
earthquake vulnerability regionally and to publicize the results. The findings
of the vulnerability assessment were made public in 1975 and 1984 for the Ward
Area, in 1980 for the Tama District, and in 1992 for the whole of the
Metropolis.

The assessment was based on the effects of an earthquake similar
to the one that occurred in 1923 (i.e. 7.9 Richter scale magnitude with an
epicentre located under Sagami Bay). The urbanized area of Tokyo was divided
into 5,017 blocks (500 m x 500 m) and a survey of vulnerability conducted for
each block using the following indicators on a scale of 5 (most vulnerable) to 1
(least vulnerable) (fig. 3.7):

Fig. 3.8. Loss assessment for the
forthcoming great Kanto earthquake in Tokyo

This survey provides a picture of the relative vulnerability among
different districts of Tokyo at the time of the earthquake. It does not take
account of cumulative losses incurred before, during, and after the earthquake,
including chains of consequences throughout the recovery period. These omissions
have been rectified by a later loss assessment that is based on an assumed
repeat of the 1923 earthquake at 6 p.m. during winter when winds are blowing
with a velocity of 6 metres per second. Damage has been estimated in three
stages: (1) immediate damage to buildings due to ground shaking, liquefaction,
and slope failure; (2) loss of life and property due to subsequent fires,
floods, and other hazards; and (3) after-effects such as the prolonged loss of
urban functions and services. Figure 3.8 summarizes the overall estimated losses
for the Tokyo Metropolis. It suggests that approximately 80 per cent of the old
built-up (Ward) district of Tokyo would be affected by ground shaking and 20 per
cent by liquefaction. In this area, loss of gas supplies would be nearly total
(98.5 per cent) and 30 per cent of the 1.5 million buildings would be burned
down. Losses in the rest of the Tokyo Metropolis would be proportionately less
but still very substantial. Loss of life is estimated at around 10,000 with
total casualties around 70,000, but these figures may be revised upwards in the
light of Kobe's recent earthquake experience. There a Richter scale 7.2 quake on
17 January 1995 caused much more damage than anyone had anticipated.

Urban disaster-prevention planning

The basic elements of disaster-prevention planning in Tokyo are
intended to increase the fire resistance of buildings, to provide residents with
safe evacuation routes to secure shelter areas, and to equip these areas with
the means to combat surrounding fires.

Fireproof buildings

The Metropolitan Government has designated 56,553 ha (or 95 per
cent) of the Tokyo Ward Area as special districts for purposes of fire
suppression and reduction. There are two types of districts: (1) fireproof
districts and (2) quasi-fireproof districts. In the former, all buildings of
more than three storeys or more than 100 m2 of floor space are
required to be built of non-flammable materials such as reinforced concrete. In
quasi-fireproof districts, fireproofing is required of only certain taller and
larger buildings; other buildings are regulated to a lesser degree. Nearly all
parts of the Ward Area are designated as quasi-fireproof districts and areas
within Loop Road 6 are designated as fireproof districts. The latter area
represents the "disaster-proof '' core of modern Tokyo.

Government subsidies to encourage the use of fireproof materials
in building construction constitute a second strand of the fireproof building
strategy. Subsidies are available to owners of buildings in the designated
fireproof districts of Tokyo as well as similar districts in Osaka, Nagoya, and
other large cities that face significant earthquake risks. So far under this
programme, 34 districts (732.3 ha) have been designated as so-called "Fireproof
Building Promotion Districts.'' Therein the main objective is to retard fire and
permit evacuation in the wake of an earthquake rather than to prevent fire
occurring. Of these districts, 28 (638.8 ha) are located in the Ward Area of
Tokyo. In other words, just over 1 per cent of Tokyo city is included in this
programme at present. The rate of the subsidy is 50 per cent (local government
25 per cent, national government 25 per cent); in fiscal year 1990, Y510 million
were spent on 198 buildings in 29 Fire-proof Acceleration Districts (i.e. Y2.6
million or US$ 25,000 per building).

Open spaces for evacuees

More than 1 million people survived fires that followed the 1923
earthquake by evacuating to large open areas such as public parks. Compared with
most cities in Europe and North America, however, Tokyo is chronically short of
public open spaces. Creation of parks, green promenades, and similar open areas
receives high priority in parts of the city where they are currently lacking.

In Tokyo, 149 evacuation sites have been officially designated.
Typically they are large parks, university or high school campuses, other public
facilities (e.g. Haneda Airport), non-flammable housing complexes such as the
so-called Metropolitan Residents' Housing, cemeteries, and riverbanks. The
largest are located in an arc close to Tokyo Bay and in a band of shrines and
parks surrounding royal residences that stretches west from the Imperial Palace.
Each is intended to provide space for evacuees at a density of not less than 1
m2 per person. According to government guidelines, no person should
have to travel more than 2 km to reach an official evacuation site.
Non-flammable buildings, parks, and open spaces, which provide the majority of
evacuation sites, are shown in figure 3.9. Other evacuation sites are also
shown.

Fig. 3.9. Fire risk, open space, and
evacuation sites

The number of evacuation sites has increased in recent years with
the departure from Tokyo to Tsukuba of many national research institutes and one
university. The grounds of these facilities are typically converted into public
parks, which are also frequently designated as evacuation sites. In addition,
the government has made use of former US military bases now returned to Japanese
control. Eleven such bases cover 1,116 ha and four of these (244 ha) are now
designated as evacuation sites. The Tokyo Metropolitan Government is also
eagerly purchasing abandoned factory sites for use as roads, parks, and housing
that incorporate the principle of disaster resistance. Finally, agricultural
land also plays a role in increasing human survivability during disasters in the
Tokyo Metropolis. Most such land is privately owned. Farmers can sell it to
developers at any time without penalty. For a long time taxes on agricultural
land were also held at very low levels but the tax laws were amended in 1991 to
remove this provision; property taxes are now set at the same level as on
built-up land. If an owner's land is designated as "Agricultural Green Space''
it is taxed at the previous low rate provided that it remains in agriculture for
at least 30 years. The new taxation system in effect divides farm land into two
different groups: land that will be converted to urban uses sooner or later; and
land that will continue to be farmed for at least 30 years. In the Tokyo
Metropolis, 53 per cent (3,983 ha) of the farm land in the Urbanization
Promotion Areas (17,520 ha) is designated as "Agricultural Green Space.''
Although such land is scattered in small parcels, these might perhaps be
amalgamated and put to work as evacuee reception areas at some time in the
future.

Evacuation routes

Successful evacuation depends in part on the availability of
suitable roads, and in much of the metropolis these are lacking. A need for
better roads is recognized both inside the built-up (Ward) area of Tokyo - where
1,705 km of new main roads have been included in urban planning documents - and
in the (Tama) hinterland, where an additional 1,368 km are so designated.
Unfortunately, owing to the high price of land and the difficulty of
negotiations with prospective sellers, only 54 per cent of these roads in the
Ward Area and 38 per cent in the hinterland have been completed.

Urban redevelopment and land adjustment projects

Urban redevelopment projects provide a suitable - though expensive
- means of converting districts full of wooden buildings into fireproof
districts. For example, Tokyo Metropolitan Government has completed the
Shirahige-higasi District Urban Redevelopment Project (27.6 ha) on the eastern
bank of the Sumida River; three more projects are under way (Shirahige-nishi
District, 49.6 ha; Kameido-oojima-komatsugawa District, 98.4 ha;
Kouenji-eki-kita District, 4.0 ha). In each of these cases, improved disaster
resistance is the primary motivation for the project. Elsewhere, disaster
resistance is an important secondary goal of two completed urban redevelopment
projects (Nishi-ookubo District, 2.9 ha, and Iidabashi District, 2.3 ha), and
one ongoing project (Akabane-kita District, 3.5 ha). The foregoing are publicly
sponsored efforts. Private sector redevelopment projects are also being
undertaken.

Land readjustment projects are an additional means of making urban
areas less vulnerable during disasters. These projects involve realigning roads
and property boundaries so that disorderly patterns of urban sprawl can be
replaced by more coherent land-use patterns. Many of Tokyo's existing roads were
former agricultural tracks and as such they are often narrow and winding. Land
readjustment projects were successfully adopted to achieve the rationalization
of urban land uses after the Kanto earthquake of 1923 and again after the Second
World War.

Disaster-prevention bases

Since 1978 the National Land Agency has been promoting a model
project for the construction of disaster-prevention bases. The main purpose is
to strengthen disaster-prevention systems at the neighbourhood level. In the
event of a disaster such places are intended to act as bases from which disaster
countermeasures would be mounted; during normal times they serve a variety of
other disaster-prevention functions including public relations, education, and
training. So far, six bases have been completed in different parts of the
country: Kawasaki City (1980), Osaka City (1981), Nagoya City (1982), Kita Ward
of the Tokyo Metropolis (1984), Amagasaki City (1986), and Shizuoka City (1989).
Two additional bases are under construction.

One particular disaster-prevention base deserves special mention.
The Tachikawa Regional Disaster-Prevention Base is located at an airport that
was formerly a US military base. Its purpose is to provide emergency
countermeasures in the event of a widespread disaster affecting the South Kanto
area - including parts of the Tokyo Metropolis. Together with the adjacent Showa
Memorial National Governmental Park, the disaster-prevention base encompasses
180 ha. Since 1983 there has been a build-up of investment in this facility. All
related ministries, other agencies, and the Tokyo Metropolitan Government have
begun to improve the base, under the coordination of the National Land Agency.
It is intended to function as the substitute facility of the national
government's Headquarters for Disaster Countermeasures.

Comprehensive water-control measures

Flooding in the western (Tama) district of the Tokyo Metropolis is
mainly a problem of overflow from small rivers during periods of heavy rainfall,
exacerbated by increasing urban occupancy of floodplains. Here the main strategy
involves structural engineering measures such as em bankments, underground river
systems, diversion channels, and sewers. These are designed to accommodate
rainfall at the rate of 75 mm per hour (a once-in-15-year event). The eastern
half of Tokyo includes a number of so-called "zero metre areas'' (e.g. Koto
Delta) that are at or near sea level and at risk of typhoons, high tides, and
earthquake subsidence. Here, engineering responses again dominate, including
tidal dykes, coastal embankments, water gates, and inland water discharge
facilities.

Along large rivers such as the Tama in the west and the Ara and
Sumida in the east, the Ministry of Construction is promoting construction of
"super banks.'' These are wide flat-topped berms that have shown superior
ability to resist earthquakes and to protect adjacent urban areas against
floods. Property developers and landowners have welcomed the super banks because
they afford view lot sites for housing in areas that are otherwise flat. At
present, "super banks'' are found only in scattered locations but - when
connected in a continuous line - it is believed that they will afford permanent
protection to the areas that they enclosed. (They are similar in concept to the
medieval Dutch "ring dykes'' that preceded polderization and reclamation
schemes, but on a more monumental scale.)

Disaster-prevention shelter bases in the Koto Delta
District

One of the most earthquake-vulnerable districts in the Tokyo Ward
Area is the Koto Delta District, which covers about 4,500 ha between the Sumida
River and the Ara River. Most of the land here is very low-lying owing to
subsidence caused by excessive use of underground water for industrial purposes
since the late 1920s. It is barely at sea level or lower and the ground
condition is soft. Homes and industries are primarily constructed of wood and
there are a great number of petrochemical installations.

Land reclamation has dominated the history of the Koto Delta
District. After a large fire in 1657 destroyed most of the existing buildings of
Edo, including the shogun's castle, it was decided to reduce overcrowding (and
vulnerability to fire) by expanding the amount of buildable land. Refuse and
other materials were dumped along both sides of the Sumida River to create
suitable sites, and the area east of the river became a residential zone, which
was also home to many temples that were transferred there. By this means the
Koto Delta District came into existence and continued to expand throughout the
Edo era.

In the wake of the Meiji Revolution (1868), Japan became an
increasingly industrialized society and the Koto Delta District was the primary
location of industrial production in Tokyo. This situation persisted until 1960,
when protective trade and monetary controls were abolished by the national
government. That action had the effect of encouraging many private companies to
concentrate production in smaller numbers of new, very large facilities located
elsewhere. By 1964 the Tokyo Metropolitan Government had taken advantage of
these changes to acquire former factories for badly needed residential
development sites. But it was clear that the entire area was susceptible to
disaster and that a plan for disaster prevention was needed both for the
occupants of new residential developments and for existing residents living in
dense clusters of old wooden houses.

The startling effects of earthquake-induced liquefaction and
subsidence on new low-rise housing in Niigata (1964) underscored the urgency of
a disaster-prevention project for the Koto Delta District. As a result, the
Ministry of Construction proposed to develop 16 square-shaped disaster
prevention bases, each 250,000 m2 in size. This plan was modified by
replacing the square bases with cross-belt (X) shaped ones to take account of
the possibility that massive post-earthquake firestorms might occur. In the end
this proposal was abandoned because it was too costly. Finally the present
"Disaster-Prevention Shelter Base Concept'' was adopted by the Tokyo
Metropolitan Government in 1969 because it would address the dual goals of
reducing disaster and increasing the supply of housing. Six disaster-prevention
shelter bases were proposed, each having an area of 50 - 100 ha. The objective
of this plan is to secure safe open spaces to which people can evacuate within
approximately 30 minutes in the event of a large earthquake. The estimated total
cost (in 1969 prices) was Y500 billion (table 3.2).

Considerable progress has been made toward implementing this plan.
Urban redevelopment projects were adopted for Shirahige-higashi District,
Shirahige-nishi District, and Kameido-oujima-komatsugawa District; the first of
these was completed in 1985. Park development projects were adopted for
Shirahige-higashi District (Higashi-shirahige Park, 10.3 ha),
Kameido-oujima-komatsugawa District (Oujima-komatsugawa Park, 24.7 ha), and Kiba
District (Kiba Park, 24.2 ha). Fireproof building promotion projects for urban
disaster prevention were also adopted in Shirahige-nishi District, Kiba
District, Yotsugi District, Ryougoku District, Chuou-sarue District, and
Chuou-sumida District.

Creation of disaster-resistant living zones

Recently a new round of more advanced countermeasures is being
added to Tokyo's defences. These include so-called "disaster-resistant living
zones'' where residents will not be called upon to evacuate in anticipation of
future threats. The area included in a disaster-resistant living zone is roughly
the same as the service area of an elementary school or junior high school
(about 65 ha). Disaster-resistant living zones shall be surrounded by firebreaks
composed of main roads, parks, railways, and rivers. Along these firebreaks,
construction of fireproof buildings is promoted. So long as fires do not break
out within these zones, the residents are presumed to be completely safe; they
will not suffer from fires in neighbouring blocks.

Within the Tokyo Ward Area disaster-resistant living zones, a
series of additional improvements will be made. These include: widening of
passageways; improvement of areas crowded with wooden rental apartment houses;
development of parks, shopping malls, and community bases for
disaster-prevention activities; preservation of residential amenities; and
promotion of voluntary community activities for disaster prevention. The Tokyo
Metropolitan Government is now experimenting with promotion schemes for
disaster-resistant living zones in three areas of the city. However, even under
the present plan, many of the outer western neighbourhoods of the Ward Area will
not be designated as disaster-proof living zones.

Countermeasures against other aspects of disaster

Traditional problems of disaster such as building collapses and
fires have now been joined by new ones that are a consequence of recent changes
in urban infrastructure and associated technologies. In particular, the spread
of high-rise buildings and the multiplication of supporting lifelines (i.e.
electricity, city gas, telecommunications, etc.) have raised problems of
complexity and interdependence. This affects the choice of disaster
countermeasures in various ways. For example, gas systems require at least four
types of hazard adjustment: (1) earthquake shock sensors that are attached to
household gas meters and shut off supplies when strong ground motion is
detected; (2) earthquake-resistant gas pipelines to generation plants; (3)
shut-off valves on large gas holding tanks at these plants; and (4) technologies
that permit some parts of the entire gas distribution network to be isolated
from the rest when disruptions affect the system. Similar principles of
hazard-resistant design and redundancy (e.g. loops, bypasses, duplicate
facilities, multiple distribution channels, emergency standby generators;
portable satellite communications) are appropriate for infrastructure systems
that convey electricity, water, voice communications, and electronic data, among
others. Bridges, tunnels, railways, and harbour facilities pose related
network-failure problems.

Although many of the newer buildings of Tokyo are in compliance
with hazard-resistance standards, much of the city is occupied by old buildings
that do not satisfy these provisions. In addition, a variety of problems are not
adequately covered by any building controls. These include standards for glass
windows and cladding on exterior walls. Another problem that is peculiarly
modern is the presence of large numbers of day-time shoppers in the centre of
Tokyo. Many of the city's 2 million daily commuters are concentrated around
stores in the vicinity of railroad stations. These people are unfamiliar with
the local area and far removed from relatives, friends, and known environments,
so they will require special handling in the event of a disaster. The elderly
and foreigners already pose special problems, particularly with respect to
providing information and assistance about appropriate evacuation routes and
shelters. As Tokyo's role as a global city strengthens and its population ages,
these will become increasingly serious issues. All of these problems underscore
an increasing need for improved public education about disasters.

Long-range planning

Since the end of the Second World War, two long-range plans for
the Tokyo Metropolis have been completed and a third is now in progress. Unlike
its predecessors, which were both oriented to encouraging economic development,
the 1990 plan - known as "My Town Tokyo'' - is a direct attempt to redress some
of the problems that have arisen as a result of rapid development.

According to the 1990 plan, Tokyo in the future should be
organized to achieve the following goals:

· an expanding global role,· a
balanced polycentric layout,· the safety and comfort of
residents,· high levels of environmental quality,· a healthy
industrial base,· lives with a feeling of affluence,· a
lively ageing society,· a city that is open to the world.

Clearly, improved disaster management is called for if the third
of these goals is to be realized. Accordingly, the plan calls for additional
emphasis to be placed on: (a) disaster-proof construction and fireproof
construction; (b) measures to protect lifelines; (c) training of
disaster-prevention volunteers; (d) measures to prevent earthquake disasters;
and (e) development of a city-wide drainage system that can handle rainfall at
rates up to 75 mm per hour. All of these efforts will take place in a city that
is more international in outlook and function, more dependent on information
acquisition and transfer, and occupied by an ageing population. These
characteristics will have important - if not entirely foreseeable - effects on
the formulation of future disaster-mitigation programmes.

Summary outlook

As in the past, the emphasis of Tokyo's future disaster policies
and programmes will be on technologically based hazard-prevention and
hazard-management projects, but additional attention will probably be given to
integrating disaster education, voluntary private mitigation initiatives,
disaster drills, and other non-structural measures into non-structural
strategies.

Earthquakes are the primary concern, and long-term plans call for
various improved responses. Most of these are incremental changes over existing
practice, but there are significant new initiatives that involve region-wide
coordination of energy, transportation, and communications services, and special
provisions for vulnerable subgroups such as the aged, the handicapped, and
(non-Japanese-speaking) foreigners. Planning is still largely oriented toward an
offshore-centred earthquake, whereas a local onshore earthquake in the South
Kanto region may be more imminent. It is urgently necessary for the Tokyo
Metropolis to assess possible losses and to strengthen the emergency response
system against such a local earthquake.

Future adjustments to flooding are geared to the characteristics
of different areas. For lowland and waterfront districts, the preferred methods
will rely on: strengthened river banks; deeper, wider, and straighter river
channels; and sea walls. In the uplands, the emphasis will be on comprehensive
flood-control plans for specific river basins. These would include land-use
controls as well as rainfall retention and absorption measures on building
sites.

Overall, integration and coordination are watchwords of the
envisaged disaster-proof Tokyo Metropolis. Soft technologies will be integrated
with hard ones and the various organizations that are involved in emergency
response activities will be closely articulated. Finally, even though the city
of Tokyo intends to pursue an aggressive programme of countermeasures against
natural disasters, it must also be prepared to absorb some losses. The capacity
for rapid recovery and restoration still needs to be maintained and the general
quality of public facilities in many areas of the city requires upgrading -
especially during future post-disaster periods.

<http://www.keidanren.or.jp/english/policy/pol040.html>
Discussion of the recent Japanese Law on the relocation of Tokyo in the face of
earthquake risks, Japanese Federation of Economic Organizations (keidanren),
October 1997.

<http://www.infoweb.or.jp/dkb/infoecon/9605/9605-1-3.html>
Discussion of Tokyo relocation sponsored by the Dai-Ibchi Kangyo Bank, October
1997.